Air cleaned and lubricated stabilizer

ABSTRACT

A rotary stabilizer for a drill string includes a stabilizer body and a plurality of stabilizer assemblies receivable therein. Each assembly comprises a generally cylindrical stabilizer member having a shaft portion of reduced diameter at each end, a bearing block for bearingly supporting each shaft portion, and a tray member extending between the bearing blocks, and partially surrounding the stabilizer member so as to expose a portion of the outer surface thereof. Means are provided in each bearing block to direct fluid to the shaft portion for lubrication and to the stabilizer and tray members for the cleaning thereof.

United States Patent 11 1 [111 3,907,048 Gray Sept. 23, 1975 [54] AIR CLEANED AND LUBRICATED 3,303,900 2/1967 Kloesel etal. .1 175/339 STABILIZER 3,306,379 2/1967 Kloesel et a1. 175/345 3,659,663 5/1972 Dysart 175/345 X Inventor: y y, C ga y Canada 3,820,613 6/1974 White 175/345 X Assigneez Bralorne Resources Limited R27,78l 10/1973 Garrett 175/345 X Calgary, Canada Primary Exammer-Dawd H. Brown Flledi 1974 Attorney, Agent, or FirmAlex. E. MacRae & Co. [21] App1.No.: 520,193

[57] ABSTRACT Foreign Application priority Data A rotary stabilizer for a drill string includes a stabilizer Ma 13 1974 Canada 199603 body and a plurality of stab1l1zer assemblles recelvable y therein. Each assembly comprises a generally cylindri- 52 US. Cl. 175/325; 175/337; 175/348 cal stabllizer member having a Shfaft portion [51] Int Cl 2 E218 l7/10 E2lc 9/00 duced dlameter at each end, a bearing block for bear- [58] Field of Search 175/325, 320, 337, 339, ingly 'j each shaft and a my 175/344 346 348 37]. 308/4 A ber extending between the bearmg blocks, and partially surrounding the stabilizer member so as to expose a portion of the outer surface thereof. Means are [56] References Cited provided in each bearing block to direct fluid to the UNITED STATES PATENTS shaft portion for lubrlcation and to the stab1l1zer and ;,(l)::g,5i9 5/1315 gughes 175/345 X tray members for the cleaning thereof.

,0 7 10/1 rant 2,328,735 9/1943 Miller /346 x 7 Claims, 3 a g F gur s US Patent Sept. 23,1975 3,907,048

JZx I AIR CLEANED AND LUBRICATED STABILIZER BACKGROUND OF THE INVENTION The present invention relates to drilling in general and to an air cleaned and lubricated stabilizer for a drill string in particular.

In the drilling of the earth it has been well known to utilize stabilizers or reamers which are connected in the drill string and rotate therewith. The stabilizer is often positioned near the bit and since it has portions contacting the inside surface of the drill hole it will prevent the bit from wobbling, thereby ensuring the drilling of a straight hole and prolonging the life of the drill bit. Such stabilizers usually include a plurality of circumferentially spaced, cylindrical stabilizer members each rotatably' mounted on a shaft in the stabilizer body, having a plurality of radially projecting tungsten carbide pellets on the outer surface thereof and having a longitudinal portion thereof lying outside the stabilizer body. As the pellets wear during use of such stabilizers their effectiveness decreases and it becomes necessary to replace the stabilizer with a new one. The drill bit must be withdrawn from the bore hole, the stabilizer removed, a new one attached and the drill string reassembled.

During operation of the stabilizer it is necessary to supply the stabilizer members and the shafts with lubricant. Drill fluid, such as air, is used and it is often supplied by an intricate series of grooves and passages formed in the various structural members. This, of course, increases the manufacturing costs for a stabilizer. In addition there should be, and often is not, provision for the removal of any debris that might be picked up by the rotating stabilizer member and brought into the pocket in the stabilizer body in which the rotary member resides. Debris can reduce the effectiveness of the stabilizer by increasing the wear on the pellets; causing structural damage or evenjamming the rotary member against rotational movement.

Such prior art stabilizers also encountered difficulty in accomodating axial loads. The loads. often as not, were sustained via a bearing surface between the end face of the roller itself and its mounting portion. This type of bearing was also prone to wear due to grit and other particles being entrapped in the bearing area, a

situation which was not overcome by theprior lubricat- 7 ing systems.

SUMMARY OF THE INVENTION lizer body, which body remains connected to the drill string. The stabilizer member is integral with its shaft and drill fluid. such as air can be directed to the shaft bearing for lubrication thereof. The same air, after use in the bearing can exit around the roller member to sweep any debris away therefrom. Since the hearing or axial load sustaining zone in the present invention is between the end of the roller shaft and the bottom of a bore in its associated mounting block, the lubricating and cleaning air can carry the debris away therefrom to avoid wear of the bearing. The resulting stabilizer is inexpensive when compared to previous stabilizers and it is economical and more efficient in its operation.

In its basic form the present invention contemplates a rotary stabilizer assembly comprising a generally cylindrical roller stabilizer member having a shaft portion at each end thereof. A pair of bearing blocks are provided, each bearingly supporting a corresponding one of the shaft portions. A tray member extends between the bearing blocks and partially surrounds the roller member to expose a longitudinal portion of its outer surface. The entire assembly is adapted for insertion into a compatable receptacle in a stabilizer body. Means are provided in each bearing block to direct fluid to the associated shaft portion.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will be described in detail with references to the drawings wherein:

FIG. 1 is an isometric view of a stabilizer incorporating the present invention with one of the stabilizer assemblies removed therefrom;

FIG. 2 is a section taken along line 22 of FIG. 1; and

FIG. 3 is a section taken along line 3-3 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a partially assembled rotary stabilizer which can be coaxially assembled into a drill string a in a known manner. For the sake of simplicity the threaded ends which would normally be used for assembly to the drill string have been omitted from the drawings.

As can be seen in FIGS. 1 and 3, the stabilizer includes a generally cylindrical body 12 provided with an axially directed bore 14 through which drill fluid. such as air, can pass. Circumferentially spaced about the body 12 are a plurality of receptacles, shown generally by reference numbers 16, which receptacles are directed longitudinally of the stabilizer body. It is usual, although not necessary, to provide three such receptacles l6, evenly spaced about the body 12. Each receptacle is adapted to receive therein a rotary stabilizer assembly, to be described hereinafter.

Each receptacle 16 includes a generally rectangular opening 18 which communicates through the body 12 with the bore 14. This is perhaps best illustrated in FIG. 3 wherein the opening 18 is shown with essentially straight sides 20. At each end of each opening 18 is a well 22 which also communicates through body 12 with bore 14. Well 22 is also generally rectangular in crosssection and it is provided with side walls 24 which each lead from the outer surface-of body 12 to a ledge or step 26 having its surface in a plane perpendicular to radius of the body through the centerline of the well. Each step 26 runs parallel to the axis of the body 12. Side walls 28 extend from steps 26, parallel to side walls 24, to the bottom of the well. Each well also has an end wall 30 the boundaries of which leading from the outer surface of body 12 to bore 14 follow walls 24. steps 26 and walls 28. The end of well 22 opposite wall 30 is open and is in direct communication with opening 18.

The rotary stabilizer assembly 32 which is adapted for reception in receptacle 16 will now be described. A

rotary stabilizer member 34 is generally cylindrical in members, such as that described by W. R. Garrett in Canadian Pat. No. 888,587 issued Dec. 21, 1971 have been provided with a central bore for the reception of a shaft, on which the roller member rotates. Contrary to this prior practice, the roller member of the present invention is an integral, unitary member whereby the central stabilizer portion and the shaft portions are formed from the same stock. As is well known in the art stabilizer portion 36 is provided with a plurality of tungsten carbide reamer pellets 40 uniformly distributed over the outer surface thereof and projecting radially therefrom. Only a few of the total number of pellets found on a roller member are shown in the drawings.

Each shaft portion 38 of each roller member is adapted to rotate in an associated bearing block 42, one of which, in FIG. 1, is shown in cross-section prior to assembly to its shaft portion. Each bearing block has a body portion 44 which has a width corresponding to the separation between side walls 28 in its assocciated well 22. Each side wall of body 44 is provided with an outwardly projecting flange 46 which is adapted to rest on step 26 of the associated well 22. The overall fit of a bearing block in its associated well is intended to be a friction fit and for additional security fastening means such as cap screws or welding may be utilized to prevent any loosening of the bearing block during use of the stabilizer.

Each bearing block has a first bore 48 therein for reception of an associated shaft portion 26, the diameter of bore 48 being such that the shaft portion 38 will bearingly rotate therein. Communicating at one end with the first bore 48 is a second bore 50, which bore extends through the body 44 of the bearing block and is aligned so that when the bearing block is in its associated well the other end of the second bore will communicate with bore 14 in stabilizer body 12.

An end flange 52 is formed on the bearing block at the end thereof which would normally be adjacent the roller member 36. The outer periphery of end flange 52 is the arc of a circle, the radius thereof being greater than the radius ofa circle defined by the outermost tips of pellets 40. The top surface of bearing block 42 extends sufficiently to include end flange 52, thereby defining the limits of its circular periphery, as best seen in FIG. 1.

FIGS. 1 and 2 illustrate the remaining component of the rotary stabilizer assembly 32, namely tray member 54. Tray member 54 is formed from sheet metal and it is shaped to conform generally to the periphery of end flanges 52. Since end flanges 52 are curved over more than 180 of arc, tray member 54 must flare outwardly as at 56 in order to permit assembly of the roller member 34 to the bearing blocks 42. To that end, the tray member has side portions 58 which are formed generally tangentially to the curved portion 60 after the curved portion has covered approximately 180 of arc. End flanges 62 at each end of tray member 54 are turned inwardly towards end flange 52 of the associated bearing block 42 and are sealingly secured, as by welding, thereto. It is thus seen that each tray member 54 extends between a pair of bearing blocks 42 and partially surrounds the roller member to expose a longitudinal portion of the outer surface thereof.

It is understood that the outer dimensions of tray member 54 correspond to those of opening 18 in stabilizer body 12, just as those of each bearing block 42 correspond to those of the associated well 22. Thus, the

rotary stabilizer assembly 32 can be inserted into an associated receptacle l6 and locked therein as by welding or other fasteners with little fear of debris entering between the assembly 34 and the receptacle 16. As is shown in FIG. 1 at 64, a portion of central stabilizer portion 36, with pellets 40 therein, will project beyond the outer surface of stabilizer body 12 for contacting the inner surface of the drill hole, thereby stabilizing the drill string therein.

The tray, roller and bearing block assembly of the present invention is also advantageous as it helps maximize the roller diameter. This in turn reduces roller wear due to slower rotation and an increased surface area. As a consequence, heavy wall pipe can be used for the stabilizer body 12 in place of the castings or forgings now in use, thereby increasing the flexibility in material requirements while reducing the costs.

As can be seen from the previous statement, the overall operation of the rotary stabilizer of the present invention is essentially similar to other known stabilizers. However, with the particular structure according to the present invention there are operational differences and advantages. In particular, drill fluid such as air will flow through bore 14 in stabilizer body 12 and will also flow through second bore in each bearing block 42. This air flows into the first bores 48 to lubricate and clean the bearing assembly of the shaft portion 38 in bore 48. Thus no additional lubricant is required. In addition the air exitting from the first bores 48 is directed mainly into the tray member 54 where it swirls around and picks up any debris brought in by roller member 34. The continuous flow of air into the tray member, accompanied by the rotary motion of roller member 34 ensures that such debris is swept from the tray member and therefore does not pose a threat to the life of the stabilizer.

It is also readily apparent that as the roller members 34 wear after extended use it is only necessary to remove an assembly 32 from the stabilizer body 12 and replace it with a new one. It is not necessary to remove the entire stabilizer from the drill string as is the case with present stabilizers. A considerable saving in time and money can thus be achieved through use of the present invention.

What is claimed is:

l. A rotary stabilizer assembly for insertion into a compatible receptacle in a stabilizer body, comprising a generally cylindrical roller stabilizer member having a shaft portion of reduced diameter at each end thereof, a pair of bearing blocks. each bearingly supporting a corresponding one of said shaft portions and having means for directing fluid to said shaft portion. and a tray member extending between said bearing blocks, said tray member partially surrounding said roller member to expose a longitudinal portion of the outer surface thereof.

2. An assembly according to claim 1 wherein each of said bearing blocks is provided with a first bore to receive the corresponding shaft portion, and said means includes a second bore communicating with said first bore, said second bore being positionable in fluid communication with a fluid passage in said stabilizer body.

3. A rotary stabilizer for connection in a drill string comprising:

1. a generally cylindrical stabilizer body having an axially directed bore therethrough for the passage of drill fluid;

2. a plurality of circumferentially spaced longitudinally directed receptacles in said body, each receptacle being adapted to receive a rotary stabilizer assembly therein; and

3. said rotary stabilizer assembly including a generally cylindrical roller stabilizer member having a shaft portion of reduced diameter at each end thereof, a pair of bearing blocks, each bearingly supporting a corresponding one of said shaft portions and having means for directing fluid to said shaft portion and a tray member extending between said bearing blocks, said tray member partially surrounding said roller member to expose a longitudinal portion of the outer surface thereof.

4. A rotary stabilizer according to claim 3 wherein each of said bearing blocks is provided with a first bore to bearingly receive the corresponding shaft portion, and said means includes a second bore communicating with said first bore and positionable in fluid communication with said bore in said body.

5. A rotary stabilizer according to claim 4 wherein each of said receptacles includes a central compartment portion sized to receive one of said tray .members and a well portion at each end of said compartment portion sized to receive a corresponding bearing block.

6. A rotary stabilizer according to claim 5 wherein said compartment portion is substantially rectangular in longitudinal cross-section and extends from the outer surface of said body to the bore in said body.

7. A rotary stabilizer for connection in a drill string comprising:

1. a generally cylindrical stabilizer body having an axially directed bore therethrough for the passage of 2. a plurality of circumferentially spaced longitudi- 3. each of said openings having associated therewith at each end thereof a generally rectangular well in said body;

4. a plurality of stabilizer assemblies, each comprisi. a generally cylindrical roller stabilizer member having a central stabilizer portion and a shaft portion of reduced diameter at each end thereof:

ii. a bearing block for each of said shaft portions,

each bearing block being receivable in an associated one of said wells, having a first bore for bearing reception of its associated shaft portion and having a second bore communicating at one end with said first bore, said second bore being aligned to communicate at its other end with the bore in said body; and

iii. a tray for surrounding a portion of said central portion of said roller member, being receivable in said opening and being sealingly connectable at each end to an associated bearing block;

5. whereby when said assemblies are positioned in said body with each tray in its associated opening and each bearing block in its associated well, air from said bore in said body can be directed through said second bores to lubricate the shaft portions rotatable in the first bores, the air exitting from said first bores at least partially sweeping through said 

1. A rotary stabilizer assembly for insertion into a compatible receptacle in a stabilizer body, comprising a generally cylindrical roller stabilizer member having a shaft portion of reduced diameter at each end thereof, a pair of bearing blocks, each bearingly supporting a corresponding one of said shaft portions and having means for directing fluid to said shaft portion, and a tray member extending between said bearing blocks, said tray member partially surrounding said roller member to expose a longitudinal portion of the outer surface thereof.
 2. An assembly according to claim 1 wherein each of said bearing blocks is provided with a first bore to receive the corresponding shaft portion, and said means includes a second bore communicating with said first bore, said second bore being positionable in fluid communication with a fluid passage in said stabilizer body.
 2. a plurality of circumferentially spaced longitudinally directed receptacles in said body, each receptacle being adapted to receive a rotary stabilizer assembly therein; and
 2. a plurality of circumferentially spaced longitudinally directed substantially rectangular openings in said body communicating with said bore;
 3. each of said openings having associated therewith at each end thereof a generally rectangular well in said body;
 3. said rotary stabilizer assembly including a generally cylindrical roller stabilizer member having a shaft portion of reduced diameter at each end thereof, a pair of bearing blocks, each bearingly supporting a corresponding one of said shaft portions and having means for directing fluid to said shaft portion and a tray member extending between said bearing blocks, said tray member partially surrounding said roller member to expose a longitudinal portion of the outer surface thereof.
 3. A rotary stabilizer for connection in a drill string comprising:
 4. A rotary stabilizer according to claim 3 wherein each of said bearing blocks is provided with a first bore to bearingly receive the corresponding shaft portion, and said means includes a second bore communicating with said first bore and positionable in fluid communication with said bore in said body.
 4. a plurality of stabilizer assemblies, each comprising i. a generally cylindrical roller stabilizer member having a central stabilizer portion and a shaft portion of reduced diameter at each end thereof: ii. a bearing block for each of said shaft portions, each bearing block being receivable in an associated one of said wells, having a first bore for bearing reception of its associated shaft portion and having a second bore communicating at one end with said first bore, said second bore being aligned to communicate at its other end with the bore in said body; and iii. a tray for surrounding a portion of said central portion of said roller member, being receivable in said opening and being sealingly connectable at each end to an associated bearing block;
 5. whereby when said assemblies are positioned in said body with each tray in its associated opening and each bearing block in its associated well, air from said bore in said body can be directed through said second bores to lubricate the shaft portions rotatable in the first bores, the air exitting from said first bores at least partially sweeping through said trays to remove debris therefrom.
 5. A rotary stabilizer according to claim 4 wherein each of said receptacles includes a cenTral compartment portion sized to receive one of said tray members and a well portion at each end of said compartment portion sized to receive a corresponding bearing block.
 6. A rotary stabilizer according to claim 5 wherein said compartment portion is substantially rectangular in longitudinal cross-section and extends from the outer surface of said body to the bore in said body.
 7. A rotary stabilizer for connection in a drill string comprising: 